unable

/ʌnˈe‍ɪbə‍l/

/əˈneɪbəɫ/

unable

being incapable of or lacking the skill, means, etc. necessary for doing something

antonyms : able

(usually followed by `to') lacking necessary physical or mental ability

lacking in power or forcefulness

Examples

1. Officers on the case are unable to find a motive.

2. The jury was unable to reach a verdict.

3. She was unable to sound the alarm.

4. Users were unable to send or receive emails for two days.